Methodology for Determining the Maximum Potentially Recoverable Energy in Water Distribution Networks

Abstract

The excess pressure available in water distribution networks (WDNs) is a relevant aspect in the management and appropriate handling of water resources. If a WDN meets the minimum performance criteria (minimum pressure and maximum flow), excess pressure can occur throughout the day, which is usually lost. These excesses could be considered as potentially recoverable energy (PRE). One way of taking advantage of this energy is to find the nodes on the network where this excess pressure is evident and try to analyze the possible amount of PRE. This work presents a methodology to determine the maximum PRE in a WDN. This methodology includes the locations of the points where the installation of recovery devices leads to this maximum PRE. The method is based on reducing pressures but maintaining circulating points through the lines. Additionally, a new energy balance that allows visualizing and breaking down in more detail all the energy found in a WDN is proposed. The analysis is carried out in an extended period considering different feeding points either by gravity or pumping. Finally, a network resilience index called the Potentially Recoverable Energy Index (PREI) in WDNs is proposed, with which it is possible to diagnose and determine how much energy could be recovered from the network. Study cases presented demonstrate the effectiveness of the methodology and will allow the development of optimizations in the operation of WDNs in favor of the good management of water and energy resources.